CN110734639A

CN110734639A - composite resistive film with adjustable and controllable dielectric constant and preparation method thereof

Info

Publication number: CN110734639A
Application number: CN201910991891.4A
Authority: CN
Inventors: 周佩珩; 王睿; 陈海燕; 谢海岩; 梁迪飞
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-01-31
Anticipated expiration: 2039-10-18
Also published as: CN110734639B

Abstract

The invention belongs to the technical field of electronic materials, and particularly relates to composite resistive films with adjustable and controllable dielectric constants and a preparation method thereof.

Description

composite resistive film with adjustable and controllable dielectric constant and preparation method thereof

Technical Field

The invention belongs to the technical field of electronic materials, and particularly relates to dielectric constant adjustable composite resistive films and a preparation method thereof.

Background

With the rapid development of the information technology era, various new -generation civil and military electronic products have put forward performance requirements in the aspects of light weight, flexibility, high performance, parameter adjustability and the like in the field of electronic materials.

Under the background, -fold research and development interest is brought to the research and development of light-weight, flexible and performance parameter-adjustable resistive film materials, the existing resistive film systems are all prepared by single raw materials, can be divided into metal resistive films and nonmetal resistive films according to material categories, have the defects of heavy weight, easiness in falling, easiness in corrosion and the like for the metal resistive films, have the defects of high density, poor toughness, poor heat dissipation and the like for the nonmetal resistive films, can be divided into oil resistive films and water resistive films from the environmental protection perspective, have the defects of toxicity for the oil resistive films, environmental pollution caused by product use and the like for the resistive films, and have the advantages of price advantage, safety in production, environmental protection for the water resistive films.

The resistance film based on the prior art has the advantages that the parameters are not easy to regulate and control under fixed quality, the regulation and control range is relatively small, the application scene of the resistance film is limited, and particularly, electronic products for aerospace have various special requirements, such as performance requirements of small quality, high and low temperature impact resistance, vibration resistance and the like.

Disclosure of Invention

In order to solve the technical problems, the invention provides composite resistive films with adjustable and controllable dielectric constants and a preparation method thereof.

The specific technical scheme is as follows:

composite resistive films with adjustable and controllable dielectric constants are prepared from carbon black, carbon nanofibers, graphene, a dispersing agent, an adhesive, a solvent and a thickening agent.

The particle size of the carbon black is 35-45nm, and the mass ratio of the carbon black to the composite resistance film is 20-25: 40.

The average diameter of the carbon nanofiber is 8-10nm, the length of the carbon nanofiber is 8-12 mu m, and the mass ratio of the carbon nanofiber to the composite resistive film is 1-5: 60.

The average diameter of the graphene is 1-5 mu m, the thickness of the graphene is 100-200nm, and the mass ratio of the graphene to the composite resistance film is 1-5: 60.

The dispersant is Sodium Dodecyl Sulfate (SDS), Sodium Dodecyl Benzene Sulfonate (SDBS) or an aqueous wetting dispersant (BYK-190). The adhesive is waterborne polyurethane and accounts for 20-25:40 of the composite resistance film in mass ratio; the solvent is deionized water. The thickener is methylcellulose (mc), sodium carboxymethylcellulose (cmc) or hydroxyethyl cellulose (hec).

The formed composite resistive film is subjected to thermal annealing treatment, carbon nanofibers are effectively dispersed between carbon black and graphene, a continuous conductive network is formed, and the conductive network is loaded in a water-based polyurethane matrix material to prepare the composite resistive film with adjustable and controllable dielectric constant. The dielectric real part regulation range of the composite resistance film under the frequency of 2-18GHz reaches 112.06-13.01, the dielectric imaginary part regulation range is 115.97-11.27, and the resistivity regulation range reaches 18.464-80.381 omega cm.

The preparation method of the composite resistive film with the adjustable and controllable dielectric constant comprises the following steps:

step 1: adding carbon black, graphene and a dispersing agent into deionized water according to a ratio, and performing ball milling uniformly at room temperature to obtain a dispersed carbon black/graphene mixed dispersion liquid; the mass ratio of the carbon black to the graphene is 20-25: 2-4; the mass ratio of the dispersant to the carbon black/graphene mixture is 1-5: 100; the ball milling speed is 300 plus 400rad/min, and the ball milling time is 40-60 min.

Step 2: adding carbon nanofibers and a dispersing agent into the carbon black/graphene mixed dispersion liquid obtained in the step 1 according to a ratio, and mechanically stirring and ultrasonically vibrating at room temperature to obtain a dispersed carbon black/graphene/carbon nanofiber mixed dispersion liquid; the mass ratio of the carbon nano fiber to the mixture of the carbon black/graphene is 1-2:30, the mass ratio of the dispersing agent to the carbon nano fiber is 20-30:100, the mechanical stirring rotating speed is 800rad/min, the ultrasonic oscillation power is 400W, and the mechanical stirring and ultrasonic oscillation time is 20-30 min.

And step 3: and (3) adding the adhesive into the mixed dispersion solution of the carbon black/graphene/carbon nano fibers obtained in the step (2) according to the proportion, and mechanically stirring at room temperature to obtain the carbon black/graphene/carbon nano fiber mixed resin slurry. The mass ratio of the adhesive to the carbon black is 1.5-2: 1; the stirring speed is 200-300rad/min, and the mechanical stirring time is not less than 5 min.

And 4, step 4: adding a thickening agent into the carbon black/graphene/carbon nanofiber mixed resin slurry obtained in the step (3) according to a ratio, and mechanically stirring at room temperature; the mass ratio of the thickening agent to the mixed resin slurry obtained in the step 3 is 1:900-1000, the mechanical stirring speed is 50-100rad/min, and the mechanical stirring time is 3-5 min.

And 5: and (4) uniformly coating the composite slurry obtained in the step (4) on a substrate, drying at room temperature, placing in a vacuum oven at 60-70 ℃ for drying, cooling to room temperature, and peeling from the substrate to obtain the composite resistive film with the adjustable and controllable dielectric constant.

The graphene, the carbon nanofiber and the carbon black are compounded and applied to prepare the resistive film, so that a better resistivity regulation and control range is realized, the applicability of the resistive film is expanded, the characteristics of stable chemical performance, corrosion resistance, high and low temperature cycle impact resistance, radiation resistance and the like of the carbon nanofiber are utilized, fixed absorption on infrared light and electromagnetic waves is realized, the graphene has the characteristics of high strength, good toughness, good optical characteristics and good electric and heat conduction performance, the finally prepared composite resistive film has the characteristics of small density, corrosion resistance, good toughness and parameter regulation and control, and the preparation method is simple and feasible.

Compared with the prior art, the composite resistance film with adjustable and controllable dielectric constant, prepared by the invention, has the following beneficial effects: the preparation process is simple, high in feasibility, pollution-free in preparation process and capable of meeting the requirement of environmental protection. Compared with the existing resistance film, the prepared composite resistance film with the adjustable and controllable dielectric constant has the characteristics of easy adjustment and control of the dielectric constant and the resistivity, thin thickness, small density, light weight, impact resistance and the like.

Drawings

Fig. 1 is a photograph of a composite resistive film with controllable dielectric constant prepared in example 1.

FIG. 2 is a graph of the dielectric constant of the tunable dielectric constant composite resistive film of example 1 at a frequency of 2-18 GHz.

FIG. 3 is a graph of the dielectric constant of the tunable and dielectric constant composite resistive film of example 2 at a frequency of 2-18 GHz.

FIG. 4 is a graph of the dielectric constant of the tunable and dielectric constant composite resistive film of example 3 at a frequency of 2-18 GHz.

Detailed Description

The technical scheme of the invention is detailed below by combining the accompanying drawings and the embodiment.

Example 1

Step 1: adding 40g of a mixture of carbon black and graphene into 100g of deionized water, wherein the mass ratio of the carbon black to the graphene is 25: 2; then, 1.2g of Sodium Dodecyl Sulfate (SDS) was added; and (3) carrying out ball milling at room temperature, wherein the ball milling rotation speed is 300rad/min, and the ball milling time is 60min, so as to obtain the carbon black/graphene mixed solution.

Step 2: and (2) adding 1.0g of carbon nanofibers and 0.4g of BYK-190 into the carbon black/graphene mixed solution prepared in the step (1), and simultaneously performing ultrasonic oscillation and mechanical stirring at room temperature, wherein the ultrasonic oscillation power is 400W, the mechanical stirring speed is 700rad/min, and the ultrasonic oscillation and mechanical stirring time is 30min to obtain the uniformly dispersed carbon black/graphene/carbon nanofiber mixed solution.

And step 3: and (3) adding 60g of waterborne polyurethane resin into the carbon black/graphene/carbon nanofiber mixed solution prepared in the step (2), and mechanically stirring at room temperature at the rotation speed of 200rad/min for 3min to obtain carbon black/graphene/carbon nanofiber mixed resin slurry.

And 4, step 4: and (3) adding 0.2g of sodium carboxymethylcellulose (cmc) into the carbon black/graphene/carbon nanofiber mixed resin slurry prepared in the step (3), and mechanically stirring at room temperature at the rotating speed of 60rad/min for 3min to obtain the carbon black/graphene/carbon nanofiber mixed resin slurry containing the thickening agent.

And 5: and (4) uniformly coating the carbon black/graphene/carbon nanofiber mixed resin slurry containing the thickening agent obtained in the step (4) on a glass substrate, drying at room temperature, then placing in a vacuum drying oven at 60 ℃ for baking for 12 hours, cooling to room temperature, and then peeling from the glass substrate to obtain the composite resistive film with the adjustable dielectric constant.

Fig. 2 and table 1 are a dielectric constant curve diagram and a resistivity data table of the dielectric constant adjustable composite resistive film obtained in example 1 at a frequency of 2-18GHz, and in a frequency band of 2-18 GHz: the real part of the dielectric is reduced to 58.35 from 112.06, the imaginary part of the dielectric is reduced to 21.76 from 115.97, and the resistivity is as high as 18.464 omega cm.

Example 2

Step 1: adding 40g of a mixture of carbon black and graphene into 100g of deionized water, wherein the mass ratio of the carbon black to the graphene is 23: 3; then, 1.2g of Sodium Dodecyl Sulfate (SDS) was added; and (3) carrying out ball milling at room temperature, wherein the ball milling rotation speed is 300rad/min, and the ball milling time is 60min, so as to obtain the carbon black/graphene mixed solution.

Step 2: and (2) adding 1.2g of carbon nanofiber and 0.6g of BYK-190 into the carbon black/graphene mixed solution prepared in the step (1), and simultaneously performing ultrasonic oscillation and mechanical stirring at room temperature, wherein the ultrasonic oscillation power is 400W, the mechanical stirring speed is 700rad/min, and the ultrasonic oscillation and mechanical stirring time is 30min to obtain the carbon black/graphene/carbon nanofiber mixed solution.

And 4, step 4: and (3) adding 0.4g of methyl cellulose (mc) into the carbon black/graphene/carbon nanofiber mixed resin slurry prepared in the step (3), and mechanically stirring at room temperature at the rotating speed of 60rad/min for 3min to obtain the carbon black/graphene/carbon nanofiber mixed resin slurry containing the thickening agent.

And 5: and (4) uniformly coating the carbon black/graphene/carbon nanofiber mixed resin slurry obtained in the step (4) on a glass substrate, drying at room temperature, then placing in a vacuum drying oven at 65 ℃ for baking for 12 hours, cooling to room temperature, and then peeling from the glass substrate to obtain the composite resistive film with the adjustable and controllable dielectric constant.

Fig. 3 and table 1 are a dielectric constant curve diagram and a resistivity data table of the dielectric constant adjustable composite resistive film obtained in example 2 at a frequency of 2-18GHz, and in a frequency band of 2-18 GHz: the real part of the dielectric is reduced from 26.56 to 14.55, the imaginary part of the dielectric is reduced from 21.15 to 7.326, and the resistivity is as high as 80.381 omega cm.

Example 3

Step 1: adding 40g of a mixture of carbon black and graphene into 100g of deionized water, wherein the mass ratio of the carbon black to the graphene is 21: 4; then, 1.2g of Sodium Dodecyl Sulfate (SDS) was added; and (3) carrying out ball milling at room temperature, wherein the ball milling rotation speed is 300rad/min, and the ball milling time is 60min, so as to obtain the carbon black/graphene mixed solution.

Step 2: and (2) adding 1.2g of carbon nanofiber and 0.4g of BYK-190 into the carbon black/graphene mixed solution prepared in the step (1), and simultaneously performing ultrasonic oscillation and mechanical stirring at room temperature, wherein the ultrasonic oscillation power is 400W, the mechanical stirring speed is 700rad/min, and the ultrasonic oscillation and mechanical stirring time is 30min to obtain the carbon black/graphene/carbon nanofiber mixed solution.

FIG. 4 and Table 1 are a graph of dielectric constant and a data table of resistivity of the dielectric constant adjustable composite resistive film obtained in example 3 at a frequency of 2-18GHz, and in a frequency band of 2-18 GHz: the real part of the dielectric is reduced to 13.01 from 31.29, the imaginary part of the dielectric is reduced to 11.27 from 36.13, and the resistivity is as high as 44.452 omega cm.

TABLE 1

Table 1 is a table of resistivity data of the composite resistive films with adjustable dielectric constants of examples 1, 2 and 3.

In conclusion, the preparation process of the dielectric constant adjustable composite resistance film is simple, high in feasibility and free of pollution in the preparation process, and meets the requirement of environmental protection. The composite resistive film with adjustable and controllable dielectric constant, which is prepared by the invention, has the characteristics of environmental protection, uniform dispersion, adjustable and controllable parameters and the like, and the regulation range of the real part of the dielectric reaches 112.06-13.01 and the regulation range of the imaginary part of the dielectric reaches 115.97-11.27 under the frequency of 2-18 GHz; the resistivity control range reaches 18.464-80.381 omega cm.

Claims

1, kinds of dielectric constant regulatable and controllable composite resistance film, characterized by:

the preparation raw materials comprise: carbon black, carbon nanofibers, graphene, a dispersant, a binder, a solvent, and a thickener;

the particle size of the carbon black is 35-45nm, and the mass ratio of the carbon black to the composite resistance film is 20-25: 40;

the average diameter of the carbon nanofiber is 8-10nm, the length of the carbon nanofiber is 8-12 mu m, and the mass ratio of the carbon nanofiber to the composite resistive film is 1-5: 60;

the average diameter of the graphene is 1-5 mu m, the thickness of the graphene is 100-200nm, and the mass ratio of the graphene to the composite resistance film is 1-5: 60;

the dispersant is Sodium Dodecyl Sulfate (SDS), Sodium Dodecyl Benzene Sulfonate (SDBS) or an aqueous wetting dispersant BYK-190; the adhesive is water-based and accounts for 20-25:40 of the mass ratio of the composite resistance film; the solvent is deionized water; the thickener is methyl cellulose mc, sodium carboxymethyl cellulose cmc or hydroxyethyl cellulose hec.

In the composite resistive film with the adjustable and controllable dielectric constant: the carbon nanofibers are dispersed between the carbon black and the graphene, and form a continuous conductive network, and the conductive network is loaded in the water-based adhesive; the regulation range of the dielectric real part reaches 112.06-13.01 under the frequency of 2-18GHz, the regulation range of the dielectric imaginary part reaches 115.97-11.27, and the regulation range of the resistivity reaches 18.464-80.381 omega cm.

2. The dielectric constant adjustable composite resistive film as recited in claim 1, wherein the adhesive is an aqueous polyurethane resin.

3. The dielectric constant tunable composite resistive film of claim 1, wherein the method of making comprises the steps of:

step 1: adding carbon black, graphene and a dispersing agent into deionized water according to a ratio, and performing ball milling uniformly at room temperature to obtain a uniformly dispersed carbon black/graphene mixed dispersion liquid; the mass ratio of the carbon black to the graphene is 20-25: 2-4; the mass ratio of the dispersant to the carbon black/graphene mixture is 1-5: 100; the ball milling speed is 300 plus 400rad/min, and the ball milling time is 40-60 min;

step 2: adding carbon nanofibers and a dispersing agent into the carbon black/graphene mixed dispersion liquid obtained in the step 1 according to a ratio, and mechanically stirring and ultrasonically vibrating at room temperature to obtain a dispersed carbon black/graphene/carbon nanofiber mixed dispersion liquid; the mass ratio of the carbon nano fiber to the mixture of the carbon black/graphene is 1-2:30, the mass ratio of the dispersing agent to the carbon nano fiber is 20-30:100, the mechanical stirring rotating speed is 800rad/min, the ultrasonic oscillation power is 400W, and the mechanical stirring and ultrasonic oscillation time is 20-30 min;

and step 3: adding the adhesive into the mixed dispersion solution of the carbon black/graphene/carbon nano fibers obtained in the step 2 according to the proportion, and mechanically stirring at room temperature to obtain carbon black/graphene/carbon nano fiber mixed resin slurry; the mass ratio of the adhesive to the carbon black is 1.5-2: 1; the stirring speed is 200 plus 300rad/min, and the mechanical stirring time is not less than 5 min;

and 4, step 4: adding a thickening agent into the carbon black/graphene/carbon nanofiber mixed resin slurry obtained in the step 3 according to the proportion, and mechanically stirring at room temperature; the mass ratio of the thickening agent to the mixed slurry obtained in the step 3 is 1:900-1000, the mechanical stirring rotating speed is 50-100rad/min, and the mechanical stirring time is 3-5 min;